java GBK字符转换成为UTF-8编码字符

import java.util.HashMap;
import java.util.Map;
/**
 * 创建日期: 2014-04-18 10:36:25
 * 作者: 黄飞
 * mail：huangfei8087@163.com 834865081@qq.com
 * ©版权归作者全部
 * */
public class ConverFromGBKToUTF8 {
	public static void main(String[] args) {
		try {
			ConverFromGBKToUTF8 convert = new ConverFromGBKToUTF8();
			String fullStr = convert.gbk2utf8("半角变拳脚,quanjiao "); 

			System.out.println( fullStr  ) ;
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	private StringUtil chinese(String chinese){
		StringUtil util = new StringUtil();
		char[]chars = chinese.toCharArray() ;
		int index = 0 ;
		StringBuffer buffer = new StringBuffer();
		for(char c : chars){
			String temp = String.valueOf(c) ;
			if(temp.getBytes().length == 1){
				util.map.put( index , temp ) ;
			}else{
				buffer.append( temp );
			}
			index++;
		}
		util.chinese = buffer.toString() ;
		return util ;
	}

	public String gbk2utf8(String chenese) {
		StringUtil strUtil = chinese( chenese ) ;
		char c[] = strUtil.chinese.toCharArray( ) ;
		byte[] fullByte = new byte[3 * c.length];
		for (int i = 0; i < c.length; i++) {
			int m = (int) c[i];
			String word = Integer.toBinaryString(m);

			StringBuffer sb = new StringBuffer();
			int len = 16 - word.length();
			for (int j = 0; j < len; j++) {
				sb.append("0");
			}
			sb.append(word);
			sb.insert(0, "1110");
			sb.insert(8, "10");
			sb.insert(16, "10");

			String s1 = sb.substring(0, 8);
			String s2 = sb.substring(8, 16);
			String s3 = sb.substring(16);

			byte b0 = Integer.valueOf(s1, 2).byteValue();
			byte b1 = Integer.valueOf(s2, 2).byteValue();
			byte b2 = Integer.valueOf(s3, 2).byteValue();
			byte[] bf = new byte[3];
			bf[0] = b0;
			fullByte[i * 3] = bf[0];
			bf[1] = b1;
			fullByte[i * 3 + 1] = bf[1];
			bf[2] = b2;
			fullByte[i * 3 + 2] = bf[2];
		}
		String reutrnStr = null ;
		try {
			reutrnStr = new String(fullByte, "UTF-8");
		} catch (Exception e) {
		}
		StringBuffer returnBuffer = new StringBuffer(  reutrnStr );
		for(Map.Entry<Integer, String> entry : strUtil.map.entrySet()){
			returnBuffer.insert(entry.getKey() , entry.getValue() ) ;
		}

		return returnBuffer.toString() ;
	}
}

class StringUtil{
	public String chinese ; 

	public Map<Integer , String> map = new HashMap<Integer, String>();
}